also iridium, osmium, rodium are others, Seadude is correct that in a funny way offbeat way, there may be other elements hereto undiscovered if you research Dr. Walter Russell and his alternative periodic table of elements and the missing spots you'll see what I mean but generally speaking:

Silver gold platinum palladium with other platinum group elements like osmium and iridium followed by semi-precious metals like copper and nickel

Platinum

Palladium

Others are;

Platinum

Copper

Pladium

No one knows, it's all a mystery. The person who knows would be a genius. I would contact Steven Hawking for a theory.